Glucose-6-phosphate dehydrogenase is a rate-controlling enzyme of the pentose phosphate pathway (PPP) that catalyzes the oxidative dehydrogenation of glucose-6-phosphate to produce glucose-6-phosphate and NADPH.It is a sex-linked metabolic enzyme involved in the shunting of hexose monophosphate.

Cd²⁺:0.606 mM, Cu²⁺:1.718 mM, Al³⁺:1.299 mM, Zn²⁺:0.321 mM

Methods: Glucose-6-phosphate dehydrogenase (G6PD) was extracted from the liver of Pelteobagrus fulvidraco and purified using affinity chromatography. The Michaelis constant (Km) and maximum reaction velocity (Vmax) of G6PD for the substrate glucose-6-phosphate (G6P) and the coenzyme NADP⁺ were determined.
Results: Kinetic parameters showed that the Km value of G6PD for G6P was 0.479 mM, the Km for NADP⁺ was 0.029 mM, and the Vmax was 2.83 U/ml [1].
Methods: Different concentrations of metal ions (Cu²⁺, Al³⁺, Zn²⁺, and Cd²⁺) were added to the G6PD enzymatic reaction system. The enzymatic activities under various concentrations were measured, with the activity of the group without metal ion treatment set as the 100% reference value.
Results: Based on the experimental data, the IC₅₀ values of G6PD under Cu²⁺, Al³⁺, Zn²⁺, and Cd²⁺ treatment were 1.718 mM, 1.299 mM, 0.321 mM, and 0.606 mM, respectively. Additionally, copper and aluminum ions exhibited competitive inhibition, with Ki values of 0.175 mM and 0.056 mM, respectively. Zinc and cadmium ions exhibited linear mixed-type inhibition; the Kis and Kii values for zinc were 0.002 mM and 0.216 mM, respectively, while those for cadmium were 0.186 mM and 3.466 mM [1].
Methods: Cellular validation: Due to the lack of a stable cell line for Pelteobagrus fulvidraco, an ovary cell line (CCO) from Ictalurus punctatus, a closely related species in the order Siluriformes, was used to analyze the effects of metal ions on G6PD mRNA expression and enzymatic activity.
Results: Under low concentrations of metal ion treatment, both the mRNA expression and enzymatic activity of G6PD increased, whereas they significantly decreased under high concentrations, indicating a dose-dependent biphasic effect of metal ions on G6PD [1].